The present invention relates to multi-channel neural stimulators, and more particularly to a multi-channel neural stimulator that includes the ability to minimize channel interaction.
A neural stimulator provides electrical stimulation pulses to selected body tissue or nerves through one or more electrodes for the purpose of providing a desired therapeutic effect, e.g., to relive pain, to treat urinary incontinence, to aid a profoundly deaf person to hear, to treat a disease, or the like. A multichannel neural stimulator provides the capability of stimulating multiple tissue sites simultaneously with different levels of stimulation, e.g., with different current pulse amplitudes, applied to each stimulation site.
Representative neural stimulation systems are disclosed in U.S. Pat. Nos. 4,400,590; 5,324,316; 5,571,148; 5,603,726; 5,824,022; 6,308,101; and in International Publication WO 02/09808 A1, which patents and publication are incorporated herein by reference.
When multiple electrodes are stimulated simultaneously, electrical interactions can arise. See, e.g., Stickney et al., “Channel Interaction and Speech Processing Strategies for Cochlear Implants”, Univ. of Texas at Dallas, House Ear Institute and Insonus Medical, Inc. Joint Presentation Report (Poster Presentation); Stickney et al. “Electrode Interaction and Speech Intelligibility in Mutlichannel Cochlear Implants”, UC Irvine Department of Otolaryngology (Poster Presentation); and Boex, et al., “Electrode interactions in Clarion Subjects”, University Hospitals, Geneva, Switzerland (Poster Presentation), which poster presentations are incorporated herein by reference.
It is generally known that channel interaction can be reduced by decreasing the current levels delivered to each electrode, improving electrode positioning and design, or using signal processing strategies or approaches that stimulate electrodes sequentially. The present invention provides another approach for minimizing channel interaction in a multichannel neural stimulator, such as a cochlear implant.